I. NOTES ON COSTA RICAN FORMICARIID^. By M. a. Carriker, Jr. While recently going over the Formicariidse in the collection of the Carnegie Museum, I made several interesting discoveries relating to the Costa Rican material collected by myself in the years from 1902 to 1907. Thinking that perhaps they may be of interest to others working in the same field, I venture to make them known. Myrmotherula axillaris (Vieillot). Two males and two females were collected in September and Oc-tober, 1904, on Sicsola River, in the southeastern part of Talamanca. Myrmotherula tne/cena was also taken in the same locality. I believe this to be the first record of the presence of Myrmotherula axillaris in Costa Rica, making a total of four species of the genus now known to inhabit that country. Cercomacra tyrannina crepera (Bangs). In the Auk for 1901, p. 35, Mr. Bangs describes a new ant-thrush as Cercomacra crepera, giving as the type locality Divala, Chiriqui, and states that it is distinguished from Cercomacra tyrannina by very much darker coloration throughout. He also states that this form re-places Cercomacra tyrannina in Chiriqui and Nicaragua. Later in his article " On a Collection of Birds from Western Costa Rica," Auk, Vol. XXIV, p. 296, he places the form of Cercotnacra, taken in the Terraba Valley of Costa Rica, under his crepera, as C. tyrannina crepera (Bangs). Upon examination of my specimens of this species, I am forced to the conclusion that Mr. Bangs has erred in the determination of his Terraba specimens, and furthermore that there is room for doubt as to the range of Cercomacra tyrannina crepera as given by him. I have before me six males and five females from the Pacific slope, distributed as follows : Bebedero de Guanacaste, i S', April, 1906. Pozo Azul de Pirris, 2 9, May and June, 1902. El Pozo de Terraba, 3 d^, June, 1907. 8
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